81303529 has 2 divisors, whose sum is σ = 81303530. Its totient is φ = 81303528.

The previous prime is 81303517. The next prime is 81303539. The reversal of 81303529 is 92530318.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78234025 + 3069504 = 8845^2 + 1752^2 .

It is a cyclic number.

It is not a de Polignac number, because 81303529 - 2¹⁷ = 81172457 is a prime.

It is a super-3 number, since 3×81303529³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 81303529.

It is not a weakly prime, because it can be changed into another prime (81303539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40651764 + 40651765.

It is an arithmetic number, because the mean of its divisors is an integer number (40651765).

Almost surely, 2^81303529 is an apocalyptic number.

It is an amenable number.

81303529 is a deficient number, since it is larger than the sum of its proper divisors (1).

81303529 is an equidigital number, since it uses as much as digits as its factorization.

81303529 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 81303529 is about 9016.8469544514. The cubic root of 81303529 is about 433.2146475092.

The spelling of 81303529 in words is "eighty-one million, three hundred three thousand, five hundred twenty-nine".